KR200279803Y1 - A Water Purification Plant With Filter and Adsorber - Google Patents

Abstract

It is an object of the present invention to provide a water purification system having an integrated filtration / adsorbent paper aimed at improving water purification and reducing installation and operating costs.

The present invention provides a multi-layered filtration / adsorption layer in which filtration and adsorbents are sequentially installed between agglomerated sedimentation basin and purified water, and effectively removes disinfection by-products (HAA, Haloacetic acids) and trace organics from purified water. In addition, it can be easily applied to existing water purification plants to reduce installation costs and reduce operating expenses.

Description

Water Purification System with Integrated Filtration / Sorption Paper {A Water Purification Plant With Filter and Adsorber}

The present invention relates to a water purification system having an integrated filtration / adsorptive paper, and particularly, to a filter / adsorber paper having a multi-layer structure, which can be easily applied to an existing water treatment plant as well as disinfection by-products ( It relates to a water purification system with integrated filtration / adsorbent paper which allows for improved water quality such as removal of precursors for the control of HAA, Haloacetic acids, reduction of chlorine requirements and treatment of intermittently expected taste and odor. .

In general, it is well known that raw water taken from rivers or lakes is not suitable for drinking as it is, and after that, water is supplied to each consumer after a series of purified water treatments. Raw water first precipitates the sand and solids contained in the raw water, and then removes microorganisms by chlorine disinfection and then sends them to the mixing site of the water purification plant. In the mixed paper, flocculation chemicals are administered to remove the solids from the sedimentation basin, and the fine solids which do not settle out in the sand filter are filtered out. Finally, a constant is supplied to each customer.

However, in the conventional water purifier as described above, the particulate solids are removed, but the dissolved substances remain and microorganisms and algae are generated in the drain pipe, and there is a problem of strange taste and smell in the water, especially for sterilization purposes. In the case of disinfection by administering chlorine, there is a problem that chlorine and dissolved organic matter react to generate disinfection by-products harmful to the human body as shown in the following table.

Water quality item Water quality standard Water Quality Status Remarks General item Turbidity (NTU) Current <0.5EPA Standard <0.3 2.5 to 548 (raw water) 0.1 to 0.3 (integer) Satisfied with the existing process pH - 6.1-9.4 pH adjustment required Taste, smell Tasteless and odorless none Likely to thrive on algae Birds - - Filter paper blockage problem caused by synedra. Possible to solve by existing process Ammonia Properties (mg / L) 0.5 - Since 1997 it does not appear to be of high concentration. Trace hazardous substances - Not detected Not detected in raw water but requires continuous monitoring and analysis Additional Restricted Substances Boron (μg / L) 300 20-80 Satisfied with the existing process chloroform 80 7.5-22.1 Satisfied with the existing process Prospective Regulatory Substance (EPA Standard) Chlorine Disinfection Byproducts TTHM (μg / L) .80 (Stage1) .40 (Stage2) 24-61 The first stage is satisfied with the existing process, but the second stage may be exceeded. HAA5 (μg / L) .60 (Stage1) .30 (Stage2) 46.3 ~ 83.4 Possible future water quality thresholds Bromate (µg / L) .10 (Stage1) .10 / 5 (Stage2) 18.8 ~ 24.8 Difficult to introduce ozone process Protozoa Cryptosporidum) 2 Log Removal 0.15oocyst / L-not detected Not detected at significant levels but need further monitoring Giardia 3 Log Removal -

On the other hand, as an effective device to solve this problem, but using a high-purity water purification device composed of an ozone contact tank and activated carbon layer, there is a problem that the economical efficiency is lowered due to excessive installation cost and operation cost of the ozone contact tank and ozone generator, In addition, there is also a pulmonary end generated by the disinfection by-products such as harmful to the human body as shown in Table 1.

Therefore, the object of the present invention is to solve the above-mentioned shortcomings, make it economical to install and operate easily in the existing water treatment plant, and also to control the disinfection by-products (HAA, Haloacetic acids) generated during chlorine disinfection. It is to provide a water purification system with an integrated filtration / adsorbent that allows for improved water quality such as material removal, reduction of chlorine requirements and intermittent anticipated taste.

The water purification system having an integrated filtration / adsorption paper of the present invention for achieving the above object is a filtration and drainage system in which the raw water supplied from the intake paper is drained after purified water treatment through chemical mixed paper, coagulated sedimentation basin and water purification paper. Adsorbents are formed in a multi-layered structure in order to be disposed between the flocculated sedimentation basin and the purified water, and includes a filtration / adsorptive paper for removing the disinfection by-products (HAA, Haloacetic acids) and trace organics in the purified water. It features.

In addition, the filtration / adsorptive paper is provided with a concrete structure installed in contact with the flocculation sedimentation basin and the purified water, the filter medium is installed at a distance from the inner bottom of the structure, and the adsorbent is installed on the filter medium in a greater thickness than the filter medium. It features.

The filter medium is preferably sand having an effective diameter of 1.2 mm, and the adsorbent is preferably carbon (active carbon) having an effective diameter of 1.0 mm.

1 is a block diagram of a water purification system according to the present invention,

FIG. 2 is an enlarged view showing only the filtration / adsorption indicated by the symbol A in FIG. 1;

Figure 3 is a graph showing the DOC removal rate at pH adjustment,

Figure 4 is a graph showing the turbidity change of raw water, sedimentation water and filtrate,

FIG. 5 is a graph showing a change in the filter size of the filter (Unit Filter Run Volume).

6 is a graph showing monthly THMFP removal rate,

7 is a graph showing the removal rate of DOC and HAFFP5,

8, 9 is a graph showing the reaction rate of HAFFP,

10A to 10D are graphs showing monthly molecular size distribution of adsorbed organics,

11A to 11H are views showing changes in the NOM size before (passing inflow) and after (flowing out) flow of the filtration / adsorbent paper.

* Description of the symbols for the main parts of the drawings *

100: water purification system 110: distribution and mixed paper

120: coagulated sedimentation basin 130: filter / adsorber

131: filter medium 132: adsorption material

Hereinafter, with reference to the accompanying drawings will be described in detail a more preferred embodiment of the present invention.

1 is a configuration diagram of a water purification system according to the present invention, and FIG. 2 is an enlarged view showing only the filtration / adsorbent paper A indicated by reference numeral A in FIG. 1.

As shown in the drawing, the water purification system 100 according to the present invention is a "sand filtration device" in the water purification system consisting of the conventional "water intake → sedimentation → chlorine disinfection → chemical mixing → flocculation sedimentation → sand filtration → chlorine disinfection → drainage”. Instead of the filter medium 131 and the adsorbent 132 is provided with a filtration / adsorption paper 130 formed in a multi-layer structure, it is easy to install and operate in the facilities of the existing water purification equipment, the filtration / adsorption The ground 130 is a filter medium 131 installed at a predetermined distance from the general backwashing device 136 disposed at the bottom of the concrete structure 135 installed in contact with the flocculated sedimentation basin 120 and the purified water 140, the filter medium 131 ) Is composed of an adsorbent 132 installed in a larger thickness than the filter medium 131.

The filter medium 131 is sand having an effective diameter of 1.2 mm, and the adsorbent 132 is carbon (activated carbon) having an effective diameter of 1.0 mm.

This configuration is characterized in that the water introduced into the filtration / adsorption paper 130 through the distribution tank and mixed paper of the reference numeral 110, the flocculation settlement battery of 120 (carbon (activated carbon) of the filtration / adsorption paper 130 The adsorbent 132 made of) removes the disinfection by-products (HAA, Haloacetic acids) in the water, and the filter medium 131, which is a lower sand layer, filters out effluent microorganisms and unremoved solids.

In particular, the coagulation process for organic matter removal (Enhanced coagulation) (120), followed by lower organic load in the GAC Filter / Adsober (130) and filter / adsorber (GAC Filter / Adsober) Since the removal of the large molecular weight material difficult to remove at (130), the treatment efficiency and life of the filtration / adsorptive paper is extended, DOC removal rate by enhanced coagulation is 30%, HAA removal rate when adjusting the final pH to about 6.0 as a result of bench test Is expected to be 36% (see Figure 3).

In addition, the hydrophilic and low molecular weight organic matters that cannot be removed from the mixed paper 110 and the flocculation battery 120 are removed, and the target DOC removal rate of the filtration / adsorbent 130 (GAC Filter / Adsober) is 30% or more. If set, DOC removal rate in the whole process is expected to be about 50% and HAA removal rate is about 60%, which is expected to satisfy the criteria of D / DBP Rule stage 1 (see Table 1). The water passing through the filtration / adsorptive paper 130 is passed through the purified paper (140, 150) and further subjected to a series of chemical sterilization and then drained to be supplied to each of the recipients.

In addition, the backwashing of the filtration / adsorption paper 130 by the backwashing device 136 performs air and water backwashing and the backwashing method is shown in Table 2 below.

Air scour Air scour + slow backwash Rinse 2 minutes, 1.0m / min 4 minutes, 1.0m / min + 0.3m / min 7 minutes (section depending on activated carbon and water temperature)

* Filtration / adsorption zone 130 control mode: Constant flow filtration of water level maintenance by inflow flow distribution and modulating valve (Gate valve) (filtration depth = 1.2m, operation band = 0.2m)

* Backwashing can use both chlorine-containing water (reservoir) and chlorine-free water (GAC effluent).

* The backwashing standard is based on turbidity, head loss, turbidity and head loss during operating hours. The standard turbidity is 0.3 NTU and the head loss is 2.0m before and after the filter.

The backwashed water is returned to the recovery and adjustment paper 160 and then treated via the chemical mixing tank 170, the concentration tank 180, and the sludge reservoir 190.

In addition, the specifications of the activated carbon and sand (sand protective layer) used in the filtration / adsorbent 130 are as follows.

division Filtrasorb820 GAC 1020 Carbon korea Effective diameter 1.2 mm 1.0mm 1.0mm Uniformity factor 1.3 1.4 1.4 Specific 0.50 ~ 0.57kg / ㎥ 0.44kg / ㎥ - Iodine 900 mg / g 1000 mg / g - 25% expansion backwash rate 42m/hr@12.8℃ 30m/hr@10.0℃ - Head Loss (158m / day) 0.064m/m@12.8℃ 0.131m/m@10.0℃ -

* Activated carbon is used for comparison test between Calgon and Norit products sold for Filter / Adsober and activated carbon manufactured according to Norit specification by domestic manufacturers.

Experimental Example

The pilot design was constructed in the river from April 2001 to November of the same year, and the results are as follows.

Based on the pilot plant setup and initial operation results, this experiment adjusted the future experimental plan and established additional experiments (goat demand test, etc.), repair plan of pilot plant, and the like. The disinfection byproduct removal capability was operated mainly for review.

Raw water quality characteristics division DOC (mg / L) UVA (cm-1) SUVA (L / mgm) HAAFP (μg / L) pH Temp (℃) 4/6 days 3.53 0.074 2.10 126.1 9.0 15.0 5/2 days 3.32 0.067 2.02 86.6 7.2 18.5 6/5 days 5.39 0.088 1.63 156.6 6.9 24.8 7/3 days 4.03 0.074 1.84 97.3 6.8 25.5 7/18 days 4.03 0.071 1.76 117.3 7.2 26.0 8/1 day 3.90 0.066 1.69 121.3 6.7 29.5 9/3 days 4.10 0.066 1.61 55.0 9/19 days 3.74 0.062 1.66 62.9 10/9 days 3.25 0.050 1.54 87.0 11/7 days 3.30 0.069 2.09 81.0

Raw water DOC from January to February 2014 was slightly higher than the DOC concentration of 3.06 to 4.46 mg / L in the same period (2000.4 to July), which was investigated during the basic design this year.

* SUVA is 1.63 ~ 2.10L / mg · m, which is similar to the value (1.72 ~ 2.39L / mg · m) surveyed for the same period in the basic design, showing that the raw water characteristics with high hydrophilic component are similar to last year.

<GAC F / A as filter paper>

1. Solute removal function

According to the existing pilot test results, the decontamination function of the GAC filter paper showed that the treatment efficiency of both Calgon and Norit was higher than that of the general filter paper, and it was judged that it was not difficult to stably achieve the internal target of 0.2 NTU (see FIG. 4).

2.Unit Filter Run Volume (UFRV)

-The unit filter run volume is set to 435m3 / m², which operates an average of 3 days with a design flow rate of 145m / day, and all UFRVs operating from April to June exceed this standard.

-The backwash was performed based on the head loss of 2.0m during the test period, and the limit of operating time is not considered. In May, when Synedra flourished, it operated for 24 hours on the basis of 2.0m loss head and for 4 ~ 5 days in other periods (see Fig. 5).

3. Influence of Sand Specification

-No difference in the degree of layer separation or the removal efficiency of the turbidity by sand effective diameter was observed.

-There was no difference in the backwashing efficiency according to the sand uniformity coefficient, but visual observation showed that the backwater was more evenly flown when the uniformity factor was small, and when the uniformity factor was large, a small amount of congestion was observed.

<Disinfection byproduct and organic matter removal function>

1.DOC, THMFP and HAAFP removal rates

-The initial (April and May) DOC estimated to be removed by adsorption was 40-70% removed and the HAAFP removal rate was 30-55%.

THMFP is effectively removed by flocculation / precipitation.

-The DOC removal rate dropped to 30-40% in June-August with high water temperature and high biological activity, but the HAAFP removal rate increased to 65-75% (see Figures 6 and 7).

2.reactivity

-In case of raw water of returning water, HAAFP reactivity in hydrophilic component is higher than HAAFP reactivity in hydrophobic component as shown in FIG.

-GAC effluent contains a lot of hydrophilic components because the hydrophobic substance is mainly removed by adsorption at the initial stage of GAC filtration operation, resulting in high reactivity. GAC effluent from June to August is estimated to remove a lot of hydrophilic components because there are many parts that are removed by biological decomposition, resulting in a lower reacitivity (see Fig. 9).

From these results, it is estimated that HAA is more efficiently removed by biologically active filter (BAF) than activated carbon adsorption.

3.SSF Analysis

①.NOM Size

-The change of molecular weight by process is shown in Table 5 below. In April-May, organic matters with large molecular weight are mainly removed by initial adsorption, and small molecules less than 1000 Dalton are hardly removed. There are many differences before and after GAC inflow.

In the -August sample, there is almost no change in the molecular size distribution before and after GAC inflow, which indicates that even a small molecular weight of less than 1000 Daltons is removed together by biological decomposition (see FIGS. 10A to 10D).

Average molecular weight enemy Sedimentation water Calgon (3.25) April Mass mean 1958 1704 876 Number average 987 901 703 In May Mass mean 1795 1542 1045 Number average 907 650 561 August Mass mean - 1039 1114 Number average - 910 976

②.NOM structure (refer to FIG. 11A-FIG. 11H)

-NOM structure also shows that the hydrophilic component was increased in activated carbon effluent in April and May samples, unlike the raw water, as the result of NOM size. It is estimated that the hydrophobic component was mainly removed by adsorption from activated carbon.

Unlike the results of April and May, the composition of NOM structure before and after GAC inflow did not change significantly in the August sample, and hydrophilic components were also removed by biodegradation.

4.AOC Analysis

-Measurement of Assimilable Organic Carbon Changes in Precipitated Symbolic Water, Sand Filtrate Filtrate, and Activated Carbon Filtrate.

-The amount of AOC in the raw water is very high, and the AOC of the effluent flowing through the activated carbon filter paper is reduced to 20㎍AC / L by removing 96%.

-Highly biodegradable components of organic matter are high, and as shown in the following Table 6, it can be very effectively removed from activated carbon (BAF) by considering the case of July.

division Sedimentation water filtrate Calgon (3.25) July 4 490 µg AC / L 410µgAC / L 20 µg AC / L

5.BDOC analysis is shown in Table 7 below.

division SW SDW FW GAC NFW 6/5 days - - - - - 7/18 days 0.73 0.66 - 0.27 0.24 8/1 day 0.38 0.63 0.41 0.23 N / D 8/16 days 0.62 0.535 0.34 0.355 0.03 9/3 days 0.635 0.825 0.58 0.275 N / D 9/19 days 0.48 0.35 0.04 0.26 0.13 10/9 days 0.7 0.63 0.53 0.38 N / D 11/7 days 0.24 0.61 0.44 0.165 N / D 11/21 0.35 0.35 0.48 0.23 N / D

<Operation Result>

-As a result of the initial operation, the GAC filter / adsorber can fully perform the detoxification function as the filter paper and the UFRV can also achieve the target 435㎥ / ㎡.

Also, HAAFP removal rate was high at 65-75% in June-August, which is presumed to be the result of biodegradation of GAC column. Therefore, further adjustment of the experimental plan is needed to maximize the biological function of activated carbon filter paper.

As described above, according to the present invention, there is an effect of having economic efficiency that can be easily installed and operated in the existing water treatment plant, and also the removal of precursors for the control of disinfection by-products (HAA, Haloacetic acids) generated during chlorine disinfection. It has the effect of improving the water quality such as the reduction of the chlorine demand and the intermittently expected taste.

Claims (2)

In the water purification system, the raw water supplied from the water intake is drained after treatment with chemical mixed paper, flocculated sedimentation basin and purified water. A multi-layered structure in which filtration and an adsorbent are sequentially formed is disposed between the flocculated sedimentation basin and the purified water, and includes a filtration / adsorbent for removing disinfection by-products (HAA, Haloacetic acids) and trace organics in the purified water. Water purification system having an integrated filtration / adsorbent paper. According to claim 1, wherein the filtration / adsorption paper is provided with a concrete structure installed in contact with the flocculation sedimentation basin and the purified water, and the filter medium provided at a distance from the inner bottom of the structure, the adsorption material installed on the filter medium in a greater thickness than the filter medium Water purification system with integrated filtration / sorbent paper, characterized in that it comprises.